go.tools/go/types: enable another test case
go.tools/go/types: enable another test case

Working now that circular interface types are handled correcly.

R=adonovan
CC=golang-dev
https://codereview.appspot.com/16310046

karmakaze/go.tools,karmakaze/go.tools,karmakaze/go.tools,karmakaze/go.tools,karmakaze/go.tools,chenjianlong/go.tools,chenjianlong/go.tools,lattera/go.tools,lattera/go.tools,lattera/go.tools,chenjianlong/go.tools